To detect wear of a conveyor belt, JP2004-35115A discloses a wear detector of a conveyor belt in which a wear detecting layer in the belt having different color such as white rubber from an elastic layer of the belt is embedded, exposure of the wear detecting layer enabling wear to be found.
A supersonic wave thickness meter determines thickness of a conveyor belt periodically to find wear when the conveyor belt does not run.
EP 0 753 472A1 or DE19 525 326A discloses that a plurality of transponders are embedded at different depths, any of the transponders broken or dropped out being detected by an antenna comprising a transmitting coil and a sensing coil close to the running belt to enable wear of the belt to be found.
However, in JP2004-35115A or supersonic wave thickness meter, instead of determination of wear automatically, wear is determined by a person when the conveyor belt does not run.
In EP 0 753 472A1, the transponders are widely embedded so that the size and cost of the device increase.
In view of the disadvantages in the prior art, it is an object of the present invention to provide a wear detector of a conveyor belt that enables wear of the conveyor belt to be detected automatically, exactly and easily during running of the belt, its structure being simple and inexpensive.